While I'm generally a fan of YubiKeys too, I've had one break without warning. Backups are highly recommended – you can lose them too, after all.

I wanted to enable YubiKey for my Bitwarden account and feared exactly this. Now I've spent 200€ for 4 YubiKeys, so if I ever miss or break one, I will hopefully be fine. But imagine telling your grandma to buy at least 2 YubiKeys for 100€ just to make your Facebook login more secure.

I was about to say the same thing. These things are quite sturdy and if you loose your key (as people do) you retire the old one and make a new. These things are neither expensive nor irreplaceable. Of course if you loose your key it's going to hurt, as it should.

I've had a Yubi Key for almost 5 years now. Zero issues.

Source: The people who sell YubiKeys.

You know what...I have a couple spares. I'll run the experiment myself :)

I've actually put my Yubikeys through worse. They've always survived :)

These were the larger ones. Not sure how the smaller "nano" ones would perform.